Dashpot



:Patented oe;r 12. 192e.I

UNITED STATES ,.114,6o2.,604 PATENT oFFl-cs.

- FREIIONT II. BUCIIINGIIAII, or DETROIT,

MICHIGAN, A'ssIGNo To ToLnDo SCALE GOIANY, 0l' TOLEDO, OHIO, ACORPORATION OF NEW JERSEY.

DASHPOT.

. This invention relates to weighing scales, and more particularly-tomeans for damping' the vibrations or oscillatory movements of theweighing mechanism. One of the principal objects of this invention isthe provision of a vibration damping device having al means forpreventing the slopping out'and spilling of`the fluid when such deviceis in operation. y

Anothervobjeet is the provision of a dash pot which 'will preventsuddenL upward as well as Vsudden downward movement of the plunger. f

- Another object is the 'provision of a dash pot in which ,resistance toupward movement ofthe plunger is not limited to atmospheric pressure. v

Another object -is the provision of a device of this character which isapplicable to numerous types of scales, whethercountero scales ofcomparatively low capacity or those of the heavy capacity type where aneiicient retarding eiect is necessary to the successful operation of thescale.

Still another object is the provision of a dash pot which isreadilyaccessible for purpose of refilling. y

Other objects'and advantages will be apparent from the followindescription, in which reference is had to t e accompanying drawingsillustrating a preferred embodiment of'my-invention and wherein similarreference numerals designate similar parts throughout-the several vlews.l

In the drawings y Figure I is an elevational view of a scale embodyingmy invention; and

Figure II isan enlar edvertical sectional view showing the das pot andadjacent Parts.

Referring to the drawings in detail, I have illustrated my invention asincor orated 1n` a weighing scale of the so-call vportable type'. It isto be understood, however, that my 'invention may be employed kwhereveradaptable, and, as the scale per sel forms no part of myinvention, Iwill; describe it only in such detail as to explain the appli' cation ofmy invention thereto. The basel of the scale forms a housing withinwhich is contained the platform lever mechanism (not shown) supportingthe load-receiving platform 2, the base being equipped with rollers 3 tofacilitate trans 'Apuoation ma Nevember 1, 1924. serial No. 747,399

portation of the scale. end of thebase 1 is a column 4 surmounted by awatch-case-shaped housingv 5 within which is housed and supported-theloadcounterbalancing mechanism. The platform lever mechanism isoperativelyconnected Erected upon oneV by means of ya link 6 to anintermediate lever 7, the latter suitably fulcrumed within theiiaringupper portion of the column 4. The lever 7 is connected to theload-counterbalancing mechanism by means of links 8 and 9 and othermechanism (not shown).

The load-counterbalancing mechanism consists of a. pair of pendulums 10,the latter provided with curved sectors 11 suspended rom a frame 12 bymeans of liexible metallic ribbons 13. Power sectors 14 'formingintegral portions of the pendulums are connected by iiexible metallicribbons 15 lto a yoke or equalizer 16 secured to 'the upper extremity ofthe link 9. It will `be apparent that a load placed upon the platform 2would exert adownward pull on the link 6., resulting in acounter-clockwise movement of the lever 7 and through the medium of -thelinks 8 and 9 cause the pendulums to move upwardly and outwardly tocountern balancethe load. The indicator hand 17 is suitablyoperatedVthrough rack and pinion mechanism (not shown) and is adapted to swingover a graduated chart to indicate the wei t of the load.

Tie device of my invention for damping the oscillatory motions of theweighing mechanism is. connected to the consists of` a cylindricalcup-like chamber -20 within which is contained a liquiddamping medium21. Adapted to operate in the liquid 21 is a piston or plunger 22 .fixedto the lower extremity of a lyod'23, the upper end' of the rod beinconnected to an arm 24 adjustably secure in an opening in the lever 7.vA sleeve 25 surrounding the r lever 7, and

23 is provided with an internally threaded portion which receives'thethreaded end of v Atrolled and adjusted, I have provided a disk 28 fixedto the sleeve 25 normally in juxtaposition to the plunger 22,thusefectively closing the openings 27. If the retarding 'in the fluid.To prevent 'such splashing the opening 29 in the dash pot cover 30through which the sleeve and rod operate is made comparatively small toadmit the passage of only a small quantit of liquid. 'Ihe walls of theopening are ared, as at 31, and the cross sectional surface area of theupper portion of the opening is increased materially. With such aconstruction the velocityl of the fluid through the narrow portion ofthe opening 29 is relatively fast during weighing movements, but as thefluid is forced upwardly by the plunger the velocity of the fluid isproportionately decreased as the 1 area of the opening is increased, andwith the decreased velocity of the fluid the tendency of said fluid tosplash or spurt out is obviated. A

When the plunger of a dash pot is suddenthe liquid, Vthe liquid will belifted in the dash pot, leaving a partial vacuum beneath.

In order to resist such exceptional pulls the dash pot must sometimes bemadeinconveniently large. The dash pot of my invention in use is filledto a level above the throat of the opening 29 and the plunger,therefore, cannot pull a vacuum, without forcing the liquid through thenarrow throat.

In order to make it possible to ll the dash pot without disassemblingthe parts, I have provided a filler tube 32 adjacent the body portion ofthe dash got through which the liquid may be poure It also serves as agage to determine when the dash pot is filled to the proper level. Thisis indicated when the liquid reaches the flaring portion 33 of the tube.A threhded cap or cover 34 lightlly encloses the end of the filler tubeto prevent the oil from being forced out by movementlof the plunger.

The embodiment of my invention herein .shown .and described is to beregarded as illustrative onl and it is to be understood that theinvention is susceptible to variation,

modification and change within the spirit and scope of the subjoinedclaims.

I-Iaving described my invention, I claim: 1. In a ldevice of the classdescribed, in

combination, a chamber, a fluid contained therein, and an opening insaid chamber, the walls of said opening being formed to effeet adecrease in velocity of fluid in passing through said opening, the walls-of said opening constituting an addition to the fluid holding spacewithin said chamber.

2. In a device yof the class described, in combination, a container' fora uid, said container having a reduced portion, a restricted openingbetween said container and reduced'portion thereof, the walls of saidreduced portion being flared to e'ect a decrease in the velocity of thefluid in passing from the container to the reduced portion, saidcontainer adapted to be normally filled with fluid to a point above thelevel lof said opening.

3. In a device of the class described, in combination, a chamber-havingan opening, fluid filling said chamber to above the level 'of saidopening', and a plunger movable in said chamber and having its stempassing through such opening, the walls of said opening being flared toeffect a decrease in velocity of the fluidwhen the plunger is in motion.

4. In a device of the class described, in

combination, a chamber having a reduced portion, there being aconstricted opening between the larger part of said chamber and saidreduced portion, a fluid in said chamber and said opening, and a plungeradapted to operate in said chamber and having a stem passing throughsaid reduced portion, the inner walls of said reduced portion beingflared outwardlyto effectan increase in the size of the opening.

A'5. In a .device of the class described, in combination, a dash potchamber having a restricted opening, a fluid in said chamber, a plun eradapted to operate in said chamber an tending to force the contents ofsaid dash pot through said opening, the walls of said opening beingflared to effect an increase in the area of said opening.

FREMONT H. BUCKINGHAM.

